The present invention relates to a dust trap and a valve for controlling a flow through a dust trap, and, more particularly to an improved technique for mounting a valve seat in a dust trap to permit and assist in its easy removal and replacement.
In my previously issued U.S. Pat. No. 3,257,045, entitled, "DUST TRAP AND VALVE THEREFOR", patented June 21, 1966, I've given a complete description of the physical structure and the operation of dust traps including their valves, showing particularly their function in bag houses and other cleaning machines and services. But, basically, a dust trap comprises a housing, a valve seat and a valve flap, with some means for moving a valve flap into and out of engagement with a valve seat. These are mounted in enclosed systems where there is a high degree of vacuum, across the valve flap.
The inter-relationship of the valve seat and the valve flap is as critical as the relationship of a valve and valve seat in an internal combustion engine. Specifically, the valve flap must seat perfectly against the valve seat to provide optimal operation of the valve in the dust trap.
As a matter of fact, the inter-relationship of the valve seat and the flap is so critical that the valve seat must be removed and polished and ground at intervals in order to maintain optimum pressure contact relationship between the two parts.
The specific nature of the problem in removing the valve seat and grinding its surface is that it is heavy and cumbersome, and frequently is so mounted and cast into the dust trap itself that the whole dust system must be taken apart in order to regrind the surface of the valve seat. Obviously, this creates many problems in that a shut-down of a system means a loss of production of the system.
It is the first object of this invention to provide an improved valve seat and valve seat mounting means which accommodates the simple removal of the valve seat itself, without taking apart the entire dust trap system.
It is the further object of this invention to provide a replaceable valve seat in a system, whereby the replacement of the valve seat itself can take place within a very few minutes, without tying up the operation of the vacuum system.
A further object of this invention is to provide an improved supporting means for the removable valve seat whereby the valve seat can be removed from or inserted into the dust trap with simplicity.